Riveted structure



Augzs, 1945. A, H R 2,383,623

RIVETED STRUCTURE Filed May 12, 1943 J/L/I'fi ZLLE DiaEL +37 PatentedAug. 28, 1945 UNITED STATES PATENT OFFICE 2,383,623 mvn'ran STRUCTUREAlvin W. Spicer, Cuyahoga Falls, Ohio, asslgnor to The B. F. GoodrichCompanygNew York, N. Y., a corporation of NGW'YOl'k Application May 12,1943. Serial No. 486,719 3 Claims. (01. 218-29) This invention relatesto riveted structures and I skin engaged by the rivets having beenprovided with keyways to receive the keys. When it has been attempted tosecured such rivets to non-metallic skin or wall materials, such asplywood or wood veneer or fabric impregnated with thermoplastic orthermosetting materials, diiliculties have been encountered due to thefact that such nonmetallic materials have notalways hadufficientstrength about the rivet holes to prevent the expanded portionof the rivet shank from tearing through the material when the rivet wasupset, have not held the hollow rivets securely against rotation, andhave not been susceptible to ready provision of preformed keyways.

The principal objects of the present invention are to provide for strongattachment of the rivet despite weakness of the material of thenonmetallic wall to hold the rivet, to provide effective metallicreinforcement of the non-metallic wallat the zone engaged by the rivet,to form interlocking means on the rivet during the upsetting of therivet for engaging the metallic reinforcement, and to provide a singlemeans for the interlocking of a plurality of rivets.

These and other objects will appear from the following description andaccompanying drawing.

' Of the drawing:

Fig. l is a perspective view of a section of an airplane wing with aplurality of metal rivets secured thereto.

Fig. 2 is a perspective view of a rivet.

In accordance with the invention, a reinforcing strip of metal isapplied and preferably secured against the rear face of the non-metallicwall, apertures are formed in the wall and the reinforcement eitherprior to or after such application, the rivets are inserted and upset orexpanded in place, and during upsetting of the rivets, the material ofthe upset portion is formed to interlock with a rough surface of themetallic reinforcement.

Referring to the drawing, which shows an illustrative embodiment of theinvention, the numeral l0 designates the skin of an airplane wing formedof non-metallic laminated material such as plywood. Secured along theinner surface of the skin is a reinforcing strip ll of plywood, and onits face is a strip l2 of sheet metal having a knurled or otherwisesuitably roughened exposed surface I. I

The metal strip I2 is preferably secured to the skin structure, as bycement or .by being molded therewith so as to adhere thereto, although aseparate strip may be employed if desired. When the wing section ismolded by pressing wood veneer and resinous material together with heatand high molding pressure, the strip I! may be assembled with the othermaterials before the molding operation and will be adhered by theresinous material. The wing is drilled at intervals along thereinforcing strip of metal to receive the rivets Ii. These rivets are oftubular form and f preferably have a conical flange is at one end forcounter-sunk application. The other end of the rivet is interiorlythreaded as at ll. This enables the rivet to be upset by a draw-rodextending through the body of the rivet and engaging the threads tocompress the tubular wall of the rivet axially as at l8 between theflange and the threaded portion. The upset portion I8 is conformed bythe pressure in this operation to the surface I4 of the metal strip l2,thereby keying it to the strip against rotation. Preferably the metalstrip I2 is knurled to provide closely spaced upstanding teeth. However,a ribbed or grooved strip, a perforated metal strip, wire cloth ofcoarse mesh, or other suitable form of metal strip may be employed, itbeing desired that the strip provide adjacent areas of differentaltitude so that when the metal of the rivet is collapsed the dispiacedmetal is forced into the deeper areas of the face of the metal strip toform key elements for interlocking the rivet to the strip. While aknurled surface M has been shown in the drawing it will be understoodthat other surfaces also, having regular or irregular elevationsVariations may be made without departing from the scope of the inventionas it is-deflned by the following claims.

I claim:

1. A structure comprising a wall of non-metallic material, areinforcement of rough-faced metal on one face of said wall, said walland said reinforcement having aligned openings, and a hollow tubularrivet extending through said openings, said rivet having an upsetportion engaging said reinforcement and interlocked with the rough facethereof.

pered countersunk head of the illustrated embodiment has the advantage,in conjunction with the backing plate i2, of crowding the fibers of thenon-metallic material by a wedging action, thereby increasing thestrength of the material in the region of the rivet, and thecountersunk-head type of rivet is preferred in applying ice-removingapparatus to airfoils and in other locations where projecting headswould increase friction. The apertures for receiving the rivets may becountersunk to receive the heads and the largest diameter of thecountersink is preferably made less than the diameter of the rivet headso that the margin of the rivet head engages slightly over the exposedfiber ends at the surface of the airfoil and binds them in positionwhile also preventing entrance of moisture to these exposed fiber ends.Such binding and sealing of the ends of the fibers may be furtherfacilitated by relieving either the metal of the rivet or material towhich it is to be secured from the shank of the rivet outwardly butshort of the periphery of its countersunk head so that greatest pressureis sustained, and first contact in assembling occurs, at the peripheryof the head.

2. A structure comprising a wall of molded non-metallic material, areinforcement therefore of rough-faced metal at one face of said wall,said wall and said reinforcement having aligned openings, and a hollowtubular rivet extending through said openings, said rivet having a headengaging against the non-metallic material of the other face of saidwall and an upset portion engaging said reinforcement and interlockedwith the rough face thereof.

3. A structure comprising a wall of molded non-metallic material, astrip reinforcement therefore of rough-faced sheet metal adhered, to oneface of said wall, said wall and said reinforcement having a series ofaligned openings. and hollow tubular rivets extending through saidopenings, said rivets each having a head engaging against thenon-metallic material of the other face of said wall and an upsetportion engaging said reinforcement and interlocked with the rough facethereof.

' ALVIN W. SPICER.

